/Engine/Source/Editor/ContentBrowserData/Public/ContentBrowserDataSource.h
Tell the data source to remove any cached data for the filter compilation that might not be needed any more.
virtual void RemoveUnusedCachedFilterData ( const [FContentBrowserDataFilterCacheIDOwner](API\Editor\ContentBrowserData\FContentBrowserDataFilterCacheID-) & IDOwner, [TArrayView](API\Runtime\Core\Containers\TArrayView)< const [FName](API\Runtime\Core\UObject\FName) > InVirtualPathsInUse, const [FContentBrowserDataFilter](API\Editor\ContentBrowserData\FContentBrowserDataFilter) & DataFilter )